Re: Looking for Long Tooth...

[Lee Chalupa <lchalupa@seelink.org>]

Scott:

I posted the message.  I administer the AJUG Java Certification Group.
No, this is not a college homework assignment but I thank you for your post 
just the same.

p.s. I'm older than most of the buildings on college campuses.

lee



On Wed, 9 Apr 2003 09:31:04 -0400, Scott P. Smith <ssmith@scott-smith.com> 
wrote:

> I am a little surprised by this question and the other one like it a few
> weeks ago.  I have a sneaky feeling that I am helping a college student 
> do
> his homework, but I'll respond anyway.
>
> There are infinitely many ways these operators can be useful.. But I'll 
> just
> give a few examples:
>
> * Data Compression - Many data compression algorithms compress byte 
> streams
> into bit streams.  To create (and later decode) the bit streams, you need
> bitwise operators.
>
> * Non-Java Binary File I/O - When working with binary files that were
> created in C, C++, etc. you will see a lot of use of things like unsigned
> 16, and 32 bit values. Since Java doesn't support these, you have to use
> bitwise operators to put the uint16 into a Java int32. And vise versa.
>
> * Old file formats - Like the previous example.  A long time ago, (when
> dinosaurs still roamed the earth and when I was in high-school)  people 
> did
> not have much disk space.  So file formats made HEAVY use of bit fields 
> to
> store a series of boolean flags.  To read or write these flags use need -
> bitwise operators.
>
> * Arbitrarily Precision Integer Math - Math packages that implement 64, 
> 128,
> 256 bit integers, etc.  These packages use bitwise operators (at least I
> think they do).
>
> * Hardware Simulation - Hardware adders multipliers etc. are sometimes
> simulated in software using bitwise operations. Not common, but I did 
> this
> back in School.
>
> Scott Smith
>
>
> ----- Original Message -----
> From: "Lee Chalupa" <lchalupa@seelink.org>
> To: "Atlanta Java Users Group" <ajug-members@ajug.org>
> Sent: Wednesday, April 09, 2003 9:24 AM
> Subject: Looking for Long Tooth...
>
>
>> Hello:
>>
>> I would like to find some examples of business problems that are 
>> addressed
>> using
>> bitwise operators or shift operators.
>>
>> I think one of the reasons people have trouble with these two topics is
>> that they
>> seem irrelevant to their work.
>>
>> My guess is that some of our more experienced programmers used these
>> operators in the "good old days".
>>
>> Does anybody have some practical examples of where they put these
> operators
>> to good use?
>>
>> Thanks
>>
>> Lee Chalupa
>> AJUG Certification Group
>>
>>
>
>



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